sheffield



(No Model.)

L. T. SHEFFIELD.

ARTIFICIAL TOOTH.

No. 854,356. Patented Dec. 14,1886.

UNITED STATES PATENT. OFFICE.

LUOIUS T. SHEFFIELD, OF NEYV YORK, N. Y.

ARTIFICIAL TOOTH. 1

SPECIFICATION forming part of Letters Patent No, 354,356, dated December14, 1886.

Application filed August 12, 1854. Serial No. 140,359. (No model.)

To all whom it may concern:

Be it known that I, LUCIUS T. SHEFFIELD, a citizen of the United States,and a resident of the city, county, and State of New York, have inventedcertain new and useful Improvements in Artificial Dentures, of which thefollowing is a specification.

My invention relates to that class of artificial dentures in which themasticating-surfaces are upon metallic portions of the teeth providedwith outer facings of porcelain; and my invention consists in makingseparate teeth of combined metallic and porcelain blocks, adapted to besold as articles of manufacture, and to be connected to form continuousmetallic bridges or supports behind the separate porcelain facings.

My invention also consists in means, hereinafter described, forconnecting the porcelain and metallic portions of incisor and lateralteeth, and for preventing lisping.

In the drawings, Figure 1 is a side view of my improved artificialtooth; Fig. 2, a side view showing the partsdetached; Fig. 3, atransverse section; Figs. 4, 5, and 8, views illustrating differentmodes of connecting the two parts of the tooth; Fig. 6, a side view of atooth constructed to preventlisping; Fig. 7, a view showing the parts ofthe tooth illustrated in Fig. 6 as detached and in, part section.

In some classes of artificial dentures the masticating-surfacesconstitute parts of bars or bridges, supported in the mouth and facedwith porcelain blocks or pieces, which represent the natural teeth, butwhich are simply facing-pieces, serving merely an ornamental purpose andnot employed in masticating.

In order to facilitate the manufacture of this class of dentures, Iprovide separate blocks each supporting a porcelain tooth and connectedthereto, and constituting therewith a salable article of manufacture,the said blocks with their porcelain facings being adapted to be fittedto and secured upon the usual supports.

In the manufacture of the improved article the block A,which reallyconstitutes the working portion of the tooth,is secured in any suitablemanner to the porcelain piece B, the face a; of the block A being formedto correspond to the crown of a molar or bicuspid tooth, as

shown in Figs. 1 to 5 and 8, or to correspond to the biting-edge of anincisor tooth,as shown in Figs. 6 and 7.

In the drawings I have shown different modes of connecting the two partstogether. Thus the porcelain part B, corresponding in outward form to anordinary porcelain tooth, but generally thinner than the latter, may beprovided with fixed pins to, embedded in the body of the piece, as shownin Fig. 3, and the metallic portion A,preferably of nickel,though anyother suitable metal-such as goldmay be employed, is perforated toreceive the said pins, which may be riveted upon the lingual or palatalsides of the block, as shown in Fig. 3.

Where it is not desired to extend the pins completely through the block,they may be headed at their inner ends, and sockets 3 may be formed inthe block to receive a suitable cement, which is inserted in a plasticstate in the socket, and the pins are then forced into the latter untilthe two parts A B are close together, as shown in Fig. 5, in whichposition they will be confined by the hardening of the cement. I havefound that when the backings of teeth which form bridges are beveled, soas to permitthe escape of air between the teeth and gums, it is very aptto causea lisping sound. This I prevent by increasing the thickness andheight of the backing, as shown in Figs. 6 and 7. The extension 6 thusformed touches the gum, serving to close the air-passages.

Another mode of securing the porcelain portion to the backing is shownin Fig. 8,and consists in fastening an ordinary backing, i, to theporcelain portion B, by means of the usual platinum pins, and in thensoldering the backing to the metallic portion A. Instead of the platinumpins,however, I prefer in many cases to use a pin made of nickel,permanently attached to the artificial tooth crown or porcelain. Thisnickel pin is capable of 'being baked into the teeth in the same waythat the platinum pins now are, but is in many respects superior, itbeing a very refractory metal and not liable to oxidation, and, further,being much less expensive than platinum. I have discovered that it maybe used instead of the platinum pins without fracturing the teeth byvariations of expansion or by reason of any other difficulty. It isfurther obvious that a tooth- IOO crown so provided with nickel pins maybe used for attachments other than that specified in this application. k4

The teeth, consisting of combined porcelain and metallic portionsconnected as above described, or in any other suitable manner,constitute articles of manufacture, which may be sold like ordinaryporcelain teeth, for use in manufacturing that class of dentures inwhich the masticating-surfaces are of metal, the said dentures beingformed by placing the teeth in proper relative position and thensoldering the backings A together, so as to form a continuous bar.

It will be evident that the modes of connecting the facing portions B tothe backing may be used when the said backing consists of a bridge orbar formed of a continuous piece, as usual.

Without limiting myself to the precise construction and arrangement ofparts shown, I claim- 1. As a new article of manufacture, an artificialtooth consisting of metal, including the masticating-face, and providedwith an ornamental facing ofporcelain, substantially as described.

2. The combination, in an artificial tooth, of an outer ornamentalporcelain facing and an inner metallic block, including the masticat- 3cing-face, and pins connecting the two portions, substantially asdescribed.

3. The combination, in an artificial tooth, of an ornamental porcelainface provided with headed pins and a metallic socketed block, in- 5cluding the masticating-face, and a body of cement surrounding each ofthepinsin the said sockets, substantially as set forth.

4. The combination, in anartificial denture, of an outer ornamentalporcelain facing and 0 an inner metallic backing, including themasticating-face, and provided with an extension,

6, substantially as and for the purpose set forth.

In testimony whereofIhave signed my name 5 to this specification in thepresence of two subscribing witnesses.

LUCIUS T. SHEFFIELD.

Vitnesses:

GEo. H. EVANS, F. L; FREEMAN.

